1. Field of the Invention
The present invention relates to an ignition mechanism for a gas lighter that uses flint and makes sparks by rotating the spark wheel, and in particular to an ignition mechanism having a non-ignite state implemented by idling the thumb wheel.
2. Description of the Related Art
Some prior art ignition mechanisms having thumb wheels have been proposed, wherein the thumb wheel is separated from the spark wheel so that the thumb wheel can idle. Moreover, the spark wheel can not be rotated by simply rotating the thumb wheel, rendering these ignition systems impossible to ignite, so as to prevent unintentional ignition of a flame.
Such ignition mechanisms for gas lighters are disclosed in U.S. Pat. Nos. 5,547,370, 5,759,023, 5,868,561, 5,913,674, 5,971,749, 5,997,281, 6,053,727, and 6,074,198. These systems comprise ignition mechanisms in which two faces, one of the thumb wheel and one of the spark wheel are caused to mesh by pushing and rotating the thumb wheel, and caused to make sparks by the power of a finger being transferred to the spark wheel. If the thumb wheel is not pushed so that it is against the spark wheel, the ignition mechanism will not ignite and the thumb wheel idles. Various meshing-mechanism types have been proposed.
Further, a system that controls the rotation of a thumb wheel and the meshing-conjugation of a thumb wheel and a spark wheel by elastic members is disclosed in U.S. Pat. No. 5,104,313.
However, said prior art ignition mechanisms for gas lighters have problems as stated below, which are improved upon in the present invention.
First, the prior art ignition systems have problems related to their operation. In short, the ignition mechanisms ignite by making sparks caused by rotation of the spark wheel, dependent on meshing two parts having determined shapes, or friction, and do not ignite if the spark wheel is not rotated. Therefore, if the distinction between the ignite-state and the not-ignite state is not clear, the operability becomes unstable. For example, if it is not possible to positively detach the meshing mechanism in the non-ignite state between the thumb and spark wheels, it is impossible to recognize whether or not it has been switched to the ignite-state by pushing the thumb wheel, etc., and it operates over and over again in the non-ignite state. Also, in the ignition mechanism dependent solely on friction, the required push-operating force varies due to the influence of gear form of the spark wheel, hardness of the flint, etc., and the switch to an ignite-state becomes unclear, resulting in the same problem with respect to operation as the mechanism described above. On the other hand, the latter prior art have clutch-connection structures utilizing an elastic member, which serves to slide the thumb wheel on axis, so its operating method is different from ordinary operating method and operating it is unnatural and difficult.
Next, regarding assembly, the prior art ignition systems are structured so that the thumb wheel and spark wheel are caused to turn as a unit by pushing together and engaging different sized shapes. Because a gap dimension is incorporated into the design to provide for a disengaged state in which the ignition mechanism is in the normal, non-ignite state, the thumb wheel is shaky, and assembly is unstable, resulting in a product that appears to be defective and that has lower merchandising value. Also, in general, metal material is used for the spark wheel, the shaft and the thumb wheel because of its hardness and heat resistance. Therefore, if the above gap is large, when the ignition system is in the non-operate state, its metal members crash against each other and make noise, giving the lighter a poor impression as a product.
In view of the points described above, the present invention provides an ignition mechanism for a gas lighter with improved operability wherein the thumb wheel can idle, and the assembly is sure, not shaky, and the thumb wheel thereby providing a product with improved appeal.
The ignition mechanism for a gas lighter according to the present invention which solves the aforementioned problems makes sparks upon rotation of a spark wheel against which a flint is being held under pressure thereby, comprising: a shaft-shaped support-member rotatably installed in the body of the lighter, a spark wheel united with said supporting member so that it can rotate, an elastic member installed around the outside periphery of the support member on one or both sides of the spark wheel, a thumb wheel, on whose inner circumference is formed a gear-type face, installed on the outer circumference of said elastic member so that it can rotate, and can travel between the concentric position and the eccentric position with respect to the aforementioned support member by deformation of said elastic-member, a polygonal or disk-shaped engaging member installed on the inner circumference of the gear-type inner face of aforementioned thumb wheel so that it can be united with aforementioned support member and rotate, having a gear-type outer face smaller in size than said gear-type inner face of A said thumb wheel which can engage with said gear-type inner face by switching said thumb wheel to the eccentric position, wherein, when said thumb wheel is in the concentric position with respect to the support member by the elastic force of the elastic member, its engaging-stopper and engaged- member of engaging member do not engage and said thumb wheel is idled, and said thumb wheel switches to eccentric position upon deformation of the elastic member, and said spark wheel is made to rotate upon engagement of the gear-type inner face of the thumb wheel and the gear-type outer face of the engaging member by rotation of said thumb wheel.
It is preferable that said support-member have a conjoining part fitted and fixed to the center hole of the spark wheel from either side, and a shaft part around which said elastic member is installed. Further, said support member can be constituted so that on one side the engaging member is integrally formed therewith, which then penetrates through the spark wheel and thumb wheel, and the engaging member on the other side is secured to the other end thereof. It is also preferable that, adjacent to said conjoining part said engaging-member is integrally formed with said support-member, and that said elastic-member is installed between the side the spark wheel and said engaging-member. Further, said elastic member may be installed on the outside of said engaging member. It is preferable that said engaging-member is inserted into the concave part having a larger outside diameter than the engaging-member formed on the outer or inner side of the thumb wheel, and said gear-type inner face is formed on the inside circumference of said concave part.
It is preferable that the inner circumference of said elastic-member is in contact with said support-member, and that the outer circumference of said elastic-member can come in contact with the inner face of said thumb wheel, and that it is composed of an elastic material, such as rubber or soft resin, or a spring material, such as metal or resin.
According to the present invention described above, the elastic-member mounted around the support member that can rotate as a unit with the spark wheel provides for the ability of the thumb wheel to be idled, as well as to be switched between the eccentric and concentric positions with respect to the support member, and the thumb wheel is provided, on a part of its inner circumference, with a gear-type inner face capable of engaging with the gear-type outer face of the engaging-member so that they can be rotated as a unit with the support-member, and wherein when the thumb wheel is in the concentric position with respect to the support member, the gear-type inner face and the gear-type outer face do not engage, and the thumb wheel is idled, and when the thumb wheel is moved to the eccentric position the spark wheel can be caused to rotate by rotation of the thumb wheel to and therefore, the spark wheel does not turn simply by rotation of the thumb wheel as per a conventional operation, and a non-ignite state is provided by causing the thumb wheel to run idle, and the desired function is attained. Operability is improved as the ignition system of the present invention is operated to generate sparks by pushing and rotating the thumb wheel based on utilization of two meshing faces which provide surity in distinguishing whether the ignition mechanism is coupled so as to provide sparks or not, that is to say, whether the thumb wheel is idled or engaged, compared to reliance on friction as in conventional ignition mechanisms which are effected by hardness of the flint, the surface condition of the spark wheel, etc.
Also, by employment of elastic members, the gap size between the thumb wheel and the support members, and the spark wheel is reduced, eliminating shakiness and providing stable assembly. Moreover, when the thumb wheel idles, meshing points do not crash against each other and make noise, providing for smooth rotation and eliminating the possibility that the product be thought to be defective, thereby improving its merchandising appeal.